Revert to blocking startJob REST api

Fixes #316

cmd/cc-backend/server.go

@@ -25,7 +25,6 @@ import (
 	"github.com/ClusterCockpit/cc-backend/internal/config"
 	"github.com/ClusterCockpit/cc-backend/internal/graph"
 	"github.com/ClusterCockpit/cc-backend/internal/graph/generated"
-	"github.com/ClusterCockpit/cc-backend/internal/repository"
 	"github.com/ClusterCockpit/cc-backend/internal/routerConfig"
 	"github.com/ClusterCockpit/cc-backend/pkg/log"
 	"github.com/ClusterCockpit/cc-backend/pkg/runtimeEnv"
@@ -314,9 +313,6 @@ func serverShutdown() {
 	// First shut down the server gracefully (waiting for all ongoing requests)
 	server.Shutdown(context.Background())
 
-	// Then, wait for any async jobStarts still pending...
-	repository.WaitForJobStart()
-
 	// Then, wait for any async archivings still pending...
 	archiver.WaitForArchiving()
 }

internal/api/api_test.go

@@ -249,9 +249,6 @@ func TestRestApi(t *testing.T) {
 		if response.StatusCode != http.StatusCreated {
 			t.Fatal(response.Status, recorder.Body.String())
 		}
-
-		time.Sleep(1 * time.Second)
-
 		resolver := graph.GetResolverInstance()
 		job, err := restapi.JobRepository.Find(&TestJobId, &TestClusterName, &TestStartTime)
 		if err != nil {

internal/api/rest.go

@@ -123,18 +123,8 @@ func (api *RestApi) MountFrontendApiRoutes(r *mux.Router) {
 	}
 }
 
-// StartJobApiResponse model
+// DefaultApiResponse model
-type StartJobApiResponse struct {
+type DefaultJobApiResponse struct {
-	Message string `json:"msg"`
-}
-
-// DeleteJobApiResponse model
-type DeleteJobApiResponse struct {
-	Message string `json:"msg"`
-}
-
-// UpdateUserApiResponse model
-type UpdateUserApiResponse struct {
 	Message string `json:"msg"`
 }
 
@@ -790,6 +780,11 @@ func (api *RestApi) startJob(rw http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	// aquire lock to avoid race condition between API calls
+	var unlockOnce sync.Once
+	api.RepositoryMutex.Lock()
+	defer unlockOnce.Do(api.RepositoryMutex.Unlock)
+
 	// Check if combination of (job_id, cluster_id, start_time) already exists:
 	jobs, err := api.JobRepository.FindAll(&req.JobID, &req.Cluster, nil)
 	if err != nil && err != sql.ErrNoRows {
@@ -804,12 +799,27 @@ func (api *RestApi) startJob(rw http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	repository.TriggerJobStart(repository.JobWithUser{Job: &req, User: repository.GetUserFromContext(r.Context())})
+	id, err := api.JobRepository.Start(&req)
+	if err != nil {
+		handleError(fmt.Errorf("insert into database failed: %w", err), http.StatusInternalServerError, rw)
+		return
+	}
+	// unlock here, adding Tags can be async
+	unlockOnce.Do(api.RepositoryMutex.Unlock)
 
+	for _, tag := range req.Tags {
+		if _, err := api.JobRepository.AddTagOrCreate(repository.GetUserFromContext(r.Context()), id, tag.Type, tag.Name, tag.Scope); err != nil {
+			http.Error(rw, err.Error(), http.StatusInternalServerError)
+			handleError(fmt.Errorf("adding tag to new job %d failed: %w", id, err), http.StatusInternalServerError, rw)
+			return
+		}
+	}
+
+	log.Printf("new job (id: %d): cluster=%s, jobId=%d, user=%s, startTime=%d", id, req.Cluster, req.JobID, req.User, req.StartTime)
 	rw.Header().Add("Content-Type", "application/json")
 	rw.WriteHeader(http.StatusCreated)
-	json.NewEncoder(rw).Encode(StartJobApiResponse{
+	json.NewEncoder(rw).Encode(DefaultJobApiResponse{
-		Message: fmt.Sprintf("Successfully triggered job start"),
+		Message: "success",
 	})
 }
 
@@ -892,7 +902,7 @@ func (api *RestApi) deleteJobById(rw http.ResponseWriter, r *http.Request) {
 	}
 	rw.Header().Add("Content-Type", "application/json")
 	rw.WriteHeader(http.StatusOK)
-	json.NewEncoder(rw).Encode(DeleteJobApiResponse{
+	json.NewEncoder(rw).Encode(DefaultJobApiResponse{
 		Message: fmt.Sprintf("Successfully deleted job %s", id),
 	})
 }
@@ -943,7 +953,7 @@ func (api *RestApi) deleteJobByRequest(rw http.ResponseWriter, r *http.Request)
 
 	rw.Header().Add("Content-Type", "application/json")
 	rw.WriteHeader(http.StatusOK)
-	json.NewEncoder(rw).Encode(DeleteJobApiResponse{
+	json.NewEncoder(rw).Encode(DefaultJobApiResponse{
 		Message: fmt.Sprintf("Successfully deleted job %d", job.ID),
 	})
 }
@@ -987,7 +997,7 @@ func (api *RestApi) deleteJobBefore(rw http.ResponseWriter, r *http.Request) {
 
 	rw.Header().Add("Content-Type", "application/json")
 	rw.WriteHeader(http.StatusOK)
-	json.NewEncoder(rw).Encode(DeleteJobApiResponse{
+	json.NewEncoder(rw).Encode(DefaultJobApiResponse{
 		Message: fmt.Sprintf("Successfully deleted %d jobs", cnt),
 	})
 }

internal/repository/dbConnection.go

@@ -82,8 +82,6 @@ func Connect(driver string, db string) {
 		if err != nil {
 			log.Fatal(err)
 		}
-
-		startJobStartWorker()
 	})
 }
 

internal/repository/jobStartWorker.go

@@ -1,83 +0,0 @@
-// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
-// All rights reserved.
-// Use of this source code is governed by a MIT-style
-// license that can be found in the LICENSE file.
-package repository
-
-import (
-	"sync"
-	"time"
-
-	"github.com/ClusterCockpit/cc-backend/pkg/log"
-	"github.com/ClusterCockpit/cc-backend/pkg/schema"
-)
-
-type JobWithUser struct {
-	Job  *schema.JobMeta
-	User *schema.User
-}
-
-var (
-	jobStartPending sync.WaitGroup
-	jobStartChannel chan JobWithUser
-)
-
-func startJobStartWorker() {
-	jobStartChannel = make(chan JobWithUser, 128)
-
-	go jobStartWorker()
-}
-
-// Archiving worker thread
-func jobStartWorker() {
-	for {
-		select {
-		case req, ok := <-jobStartChannel:
-			if !ok {
-				break
-			}
-			jobRepo := GetJobRepository()
-			var id int64
-
-			for i := 0; i < 5; i++ {
-				var err error
-
-				id, err = jobRepo.Start(req.Job)
-				if err != nil {
-					log.Errorf("Attempt %d: insert into database failed: %v", i, err)
-				} else {
-					break
-				}
-				time.Sleep(1 * time.Second)
-			}
-
-			for _, tag := range req.Job.Tags {
-				if _, err := jobRepo.AddTagOrCreate(req.User, id,
-					tag.Type, tag.Name, tag.Scope); err != nil {
-					log.Errorf("adding tag to new job %d failed: %v", id, err)
-				}
-			}
-
-			log.Printf("new job (id: %d): cluster=%s, jobId=%d, user=%s, startTime=%d",
-				id, req.Job.Cluster, req.Job.JobID, req.Job.User, req.Job.StartTime)
-
-			jobStartPending.Done()
-		}
-	}
-}
-
-// Trigger async archiving
-func TriggerJobStart(req JobWithUser) {
-	if jobStartChannel == nil {
-		log.Fatal("Cannot start Job without jobStart channel. Did you Start the worker?")
-	}
-
-	jobStartPending.Add(1)
-	jobStartChannel <- req
-}
-
-// Wait for background thread to finish pending archiving operations
-func WaitForJobStart() {
-	// close channel and wait for worker to process remaining jobs
-	jobStartPending.Wait()
-}